"We have been very active historically in the acquisition markets, and we're positioning ourselves to do that again."

Valero will be aided by what Gorder called a strong balance sheet, low debt and significant cash. Valero's stock rose 81 cents, closing at $61.64.

Gorder didn't provide details as to what acquisitions he is considering. Valero now owns 15 refineries with a total capacity of 2.9 million barrels a day.

More than doubled

The San Antonio-based Valero has capitalized on low crude oil prices and strong gasoline demand, as its net income in the second quarter more than doubled to $1.4 billion compared with $651 million for the year-earlier period.

John Auers, senior vice president at energy consulting firm Turner, Mason & Co. in Dallas, noted that the present value of most refineries "would be pretty high."

"Refiners have done so well, and most are pretty happy with refining assets," he said. "So you've got an environment where owners are happy and for buyers - it's a high market to get into.

Selective sales?

"I don't see a wave of acquisition, but there will be selective sales," Auers added, as some companies may decide to sell plants that aren't deemed core assets. "Maybe when margins normalize a bit, there might be more opportunities for acquisitions," he said.

Valero last bought a refinery in 2011 when, under then-CEO Bill Klesse, it acquired Chevron Corp.'s Pembroke plant in Wales. Valero paid more than $1.7 billion for the refinery and related assets.

Before that, then-CEO Bill Greehey went on a buying spree in 2005, acquiring Connecticut-based refiner Premcor and adding four plants to the 15 refineries it owned at the time. Valero wanted Premcor for its refineries in Port Arthur; Lima, Ohio; Memphis, Tenn.; and Delaware City, Del.

After the Premcor acquisition and before the Pembroke purchase, Valero sold four plants and closed its Aruba refinery in the Caribbean.